Recently, interest in technology using rechargeable secondary batteries as power sources of vehicles is on the rise. Although a nickel-metal hydride (Ni-MH) battery is mainly used as a secondary battery, use of a lithium ion battery is attempted now.
Medium or large-sized battery packs, formed by stacking a plurality of battery cartridges, have various battery cartridge stacking methods or connection methods and in order to execute these methods, various structures are required and large amount of labor is required.
A battery pack generates heat during discharge and such heat is a factor which shortens the lifespan of the battery pack and reduces efficiency of the battery pack. Further, when the temperature of the battery pack is excessively low, proper output may not be provided to a vehicle. Therefore, an apparatus to maintain a proper temperature of a battery pack is required.